Displacement on a cylinder or creating a texture roller
1.Add a cylinder, adjust its scale in edit mode and cut the faces to squares with Ctrl+R, mark a seam and unwrap it.


Add a subdivision surface modifier with 3-5 viewport value and apply it.
Browse in your texture in the "Texture" properties tab.
Add a displace modifier, select your texture, set the coordinates to UV, set the Midlevel 0 or 1 to preserve the original geometry and set the strenght to a low value then apply the modifier.